fixed undo within a global command (would corrupt the buffer)

changed move within a global to behave as in SunOS
added a couple error messages

bin/ed/POSIX

@@ -48,3 +48,15 @@ Though ed is not a binary editor, it can be used (if painfully) to edit
 binary files.  To assist in binary editing, when a file containing at
 least one ASCII NUL character is written, a newline is not appended
 if it did not already contain one upon reading.
+
+Since the behavior of `u' (undo) within a `g' (global) command list is
+not specified by POSIX D11/2, it follows the behavior of the SunOS ed
+(this is the best way, I think, in that the alternatives are either too
+complicated to implement or too confusing to use):  undo forces a global
+command list to be executed only once, rather than for each line matching
+a global pattern.  In addtion, each instance of `u' within a global command
+undoes all previous commands (including undo's) in the command list.
+
+The `m' (move) command within a `g' command list also follows the SunOS
+ed implementation: any moved lines are removed from the global command's
+`active' list.

bin/ed/buf.c

@@ -165,7 +165,11 @@ getaddr(lp)
 
 	while (cp != lp && (cp = cp->next) != &line0)
 		n++;
-	return (cp != &line0) ? n : 0;
+	if (n && cp == &line0) {
+		sprintf(errmsg, "invalid address");
+		return ERR;
+	 }
+	 return n;
 }
 
 

bin/ed/ed.1

@@ -92,9 +92,9 @@ commands have the structure:
 .I [address [,address]]command[parameters]
 .RE
 .sp
-The address(es) indicate the line(s) to be affected by the command.
-If fewer addresses are given than the command accepts, then default
-addresses are supplied.
+The address(es) indicate the line or range of lines to be affected by the
+command.  If fewer addresses are given than the command accepts, then
+default addresses are supplied.
 
 .SS OPTIONS
 .TP 8
@@ -311,7 +311,7 @@ not listed below, including `{', '}', `(', `)', `<' and `>',
 matches itself.
 
 .TP 8
-\fR\\\fIc\fR
+\fR\e\fIc\fR
 Any backslash-escaped character
 .IR c ,
 except for `{', '}', `(', `)', `<' and `>',
@@ -389,28 +389,28 @@ anchors the regular expression to the end of a line.
 Otherwise, it matches itself.
 
 .TP 8
-\fR\\<\fR
+\fR\e<\fR
 Anchors the single character regular expression or subexpression
 immediately following it to the beginning of a word.
 (This may not be available)
 
 .TP 8
-\fR\\>\fR
+\fR\e>\fR
 Anchors the single character regular expression or subexpression
 immediately following it to the end of a word.
 (This may not be available)
 
 .TP 8
-\fR\\(\fIre\fR\\)\fR
+\fR\e(\fIre\fR\e)\fR
 Defines a subexpression
 .IR re .
 Subexpressions may be nested.
-A subsequent backreference of the form \fI`\\n'\fR, where
+A subsequent backreference of the form \fI`\en'\fR, where
 .I n
 is a number in the range [1,9], expands to the text matched by the
 .IR n th
 subexpression.
-For example, the regular expression `\\(.*\\)\\1' matches any string
+For example, the regular expression `\e(.*\e)\e1' matches any string
 consisting of identical adjacent substrings.
 Subexpressions are ordered relative to
 their left delimiter.
@@ -426,7 +426,7 @@ the string `abbb' (as opposed to the substring `bbb'), since a null match
 is the only left-most match.
 
 .TP 8
-\fR\\{\fIn,m\fR\\}\fR or \fR\\{\fIn,\fR\\}\fR or \fR\\{\fIn\fR\\}\fR
+\fR\e{\fIn,m\fR\e}\fR or \fR\e{\fIn,\fR\e}\fR or \fR\e{\fIn\fR\e}\fR
 Matches the single character regular expression or subexpression
 immediately preceding it at least
 .I n
@@ -735,7 +735,7 @@ An unescaped `&' in
 .I replacement
 is replaced by the currently matched text.
 The character sequence
-\fI`\\m'\fR,
+\fI`\em'\fR,
 where
 .I m
 is a number in the range [1,9], is replaced by the
@@ -912,8 +912,8 @@ that line.
 Buffer file
 .PD 0
 .TP 20
-\fR./ed.hup\fR, $HOME/ed.hup
-First and second files to which
+ed.hup
+The file to which
 .B ed
 attempts to write the  buffer if the terminal hangs up.
 
@@ -971,6 +971,10 @@ replaces any occurrences of
 .I old
 with
 .IR new .
+If the
+.I `u'
+(undo) command occurs in a global command list, then
+the command list is executed only once.
 
 If diagnostics are not disabled, attempting to quit
 .B ed

bin/ed/ed.h

@@ -237,7 +237,7 @@ void lpqueue __P((line_t *));
 void makekey __P((char *));
 char *makesub __P((int));
 char *translit __P((char *, int, int, int));
-int move __P((long));
+int move __P((long, int));
 int oddesc __P((char *, char *));
 void onhup __P((int));
 void onintr __P((int));
@@ -253,7 +253,7 @@ int catsub __P((char *, regmatch_t *, int));
 int subst __P((pattern_t *, int));
 int tobinhex __P((int, int));
 int transfer __P((long));
-int undo __P((void));
+int undo __P((int));
 undo_t *upush __P((int, long, long));
 void ureset __P((void));
 

bin/ed/re.c

@@ -71,7 +71,7 @@ optpat()
 		sprintf(errmsg, "invalid pattern delimiter");
 		return NULL;
 	} else if (*ibufp == delim) {
-		sprintf(errmsg, "no previous pattern");
+		if (!exp) sprintf(errmsg, "no previous pattern");
 		return exp;
 	} else if ((exps = getlhs(delim)) == NULL)
 		return NULL;

bin/ed/test/g3.d

@@ -0,0 +1,5 @@
+line 1
+line 2
+line 3
+line 4
+line5

bin/ed/test/g3.r

@@ -0,0 +1,5 @@
+linc 3
+xine 1
+xine 2
+xinc 4
+xinc5

bin/ed/test/g3.t

@@ -0,0 +1,4 @@
+g/./s//x/\
+3m0
+g/./s/e/c/\
+2,3m1

bin/ed/test/g4.d

@@ -0,0 +1,5 @@
+line 1
+line 2
+line 3
+line 4
+line5

bin/ed/test/g4.r

@@ -0,0 +1,7 @@
+hello
+zine 1
+line 2
+line 3
+line 4
+line5
+world

bin/ed/test/g4.t

@@ -0,0 +1,13 @@
+g/./s/./x/\
+u\
+s/./y/\
+u\
+s/./z/\
+u
+u
+0a
+hello
+.
+$a
+world
+.